Driving mechanism for bicycles.



Na. 667,594. Patented Feb. 5, 1901. c. soucv, 1R.

nmvme MECHANISM FOR sllcvcu-zs.

(Application filed. June 25, 1900.)

(No Model.)

Witnesses Inventor W Y Attorney m: NORRIS PETERS no. Pumom'nmWASHINGTON. 0. cv

llmrnn STATES ATENT GFFICEQ OYPRIEN SOUOY, JR., OF MANCHESTER, NE\VHAMPSHIRE.

DRIVING MECHANISM FOR BICYCLES.

SPECIFICATION formingpart of Letters Patent No. 667,594, dated February5, 1901.

Application filed June 25, 1900.

T0 aZZ whont it may concern:

Be it known that I, CYPRIEN SoUoY, J r., a citizen of the United States,residing at Manchester, in the county of Hillsborough and State of NewHampshire, have invented certain new and useful Improvements in DrivingMechanism for Bicycles; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates especially to the driving-gear of a bicyle andcertain chain connections for accommodating the same. The arrangement ofmy improved gears and the driving-chain are especially adapted for andperform this function only when the rear fork and stay of a bicycleframeare pivotally connected to the latter.

The object of the invention is to maintain a uniform distance betweenthe riding-saddle and the crank-hanger of a machine, this avoiding anyjerky motion of the pedals which would otherwise occur if the chainswere running directly from the small sprocket overthe large sprocket anda spring-seat and pneumatic tires were used. Hence my inventionconsists,broadly,in means whereby the chain, instead of assuming anangular course between the small and large sprockets, is permitted topass over a loose pulley of a size corresponding to that of the smallsprocket and locating the loose pulley upon a plane above that of eithersprocket, as will be fully set forth in the following specification andclaims and clearly illustrated in the drawings accompanying and forminga part of the same, of Which Figure l is a broken side elevation of abicycle to which my improvements are applied. Fig. 2 is a broken planView showing that portion of the bicycle-frame to which my improveddriving-gear is attached. Fig. 3 is a broken elevation showing adetached portion of the frame in which bearings are provided for myimproved gears.

Similar reference-letters denote corresponding parts in all the views.

A represents the Wheels.

B is the upper tube, and O the lower tube.

D is the head or socket carrying the front Serial No. 21,444. (Nomodel.)

fork and to which one end of the tubes B and O is braced in the usualmanner.

E is the perch, and F the crank-hanger to which the lower end of thetube 0 and said perch are attached by a braced joint.

In order to adapt the frame to my improved gears, I provide a bracket Gat the rear of the perch, and this is provided with bearings g g, whichcarry loose pulleys.

H is a brace connecting the lower portion of the perch E and the tube C,so as to strengthen the perch at that point to which the bracket G isattached. The rear fork I is pivotally attached att' to the bearing ofthe bracket G, and near the free end of said fork is pivotally connectedthe stay J, the upper end of said stay being loosely fitted to asuitable socket rigidly connected to the porch and acted upon by anysuitable spring, as represented at K, such construction causing thecrank-hanger to move vertically toward and away from the ground andproducing a constantly-varying forward-and-backward movement of thecrank-shaft either faster or slower than its natural rotative courserelative to the rotation of the driving-wheel at any given speed, andthis jerky movement of the crankshaft, however slight it may be, isquite sufficient to be felt by a rider having his feet upon the pedals.To arrive at this, I provide a loose pulley L, preferably grooved, as atZ, and mounted upon the pivotal connection of the fork I, and a loosesprocket M is mounted at g upon the bracket G, the driving-chain Npassing around ordinary sprockets, the larger one, 0, being mounted inthe crank-hanger F and the smaller one, P, being mounted on the hub ofthe rear or driving wheel, as shown. Both the loose pulley L and thewheel M may be grooved, so as to carry the chain N, or one of them maybe provided with teeth and made into a sprocket, as is shown at M. Thepulley L is of a diameter equal to the sprocket P on the driving-wheeland so mounted that its periphery is above that of either sprocket O P,so that the chain may never be raised or lifted from said pulley L byany yielding motion of the spring-frame, and in order that the effectmay be the same as if the chain passed over a pair of sprockets of equaldiameter, under which conditions there could be no such jerky motion ofthe cranks as above mentioned, the wheel or sprocket lWI is mountedunder the lower portion of the chain at a point to raise the chainbetween said loose pulley L and the sprocket 0, this insuring continualcontact of said chain with opposite sides of said loose pulley withoutregard to the yielding motion of the rear fork or crank-hanger.

Having described my invention, what I claim is-- 1. As a means ofpreventing any jerky motion of the cranks in a bicycle having the rearfork and stay pivotally attached to the frame, suitable drivingmechanism comprising an ordinary large and small sprocket andconnecting-chain, an intermediate loose pulley of equal diameter withsaid small sprocket and mounted on a plane above that of eithersprocket, and a loose sprocket located forward of said loose pulley andadapted to hold the chain and said pulley in contact, said chain beingin contact with both the upper and lower sides of the loose pulley.

2. In combination in a bicycle, with the perch and frame bars E, C, abracket extending rearwardly in relation to the cran k-hanger and perch,a pair of journal-bearings g, g, on said bracket, a loose pulley L andthe movable rear forks having a common axis, the crank-sprocket O, thedrive-wheel sprocket P, the axis of said loose wheel being fixed inrelation to the crank-sprocket and having its periphery in a higherplane than the periphcries of the sprockets and a loose sprocket havingits journal supported in the bearing g, substantially as described.

3. In combination in a bicycle with the frame, the crank-sprocketjournaled therein, the rear forks pivotally supported to have movementup and down, the sprocket at the rear ends of said movable forks, thechain extending between the sprockets and means to give both the upperand lower portions of the chain an angular course between the sprockets,said means comprising a loose pulley at the pivot of the rear fork withmeans for holding the lower part of the chain constantly in contact withthe pulley, said pulley being so located that the upper part of thechain always contacts therewith, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

OYPRIEN SOUOY, JR. Witnesses:

J. B. THURSTON, EMILE I-I. TARDIVEL.

